Nine medical specialty groups have released a list of 45 tests and procedures that patients often do not need - even though doctors routinely perform them. They include annual electrocardiograms, CT scans for low back pain, and chest X-rays before surgery.

Ordering these tests when they are not merited wastes money and can harm patients by exposing them to radiation and more unneeded medical procedures, the physician groups said.

Recent estimates suggest that nearly 30 percent of the money Americans spend on health care is wasted, said Dr. Christine Cassel, president of the American Board of Internal Medicine Foundation, a nonprofit organization based in Pennsylvania that is overseeing the project. But she said, “It isn’t just about cost, it’s about putting patients at risk.’’

Doctors sometimes push these tests because they are not up to date with research questioning their effectiveness or because the tests generate revenue. But the physicians involved in the project said patients also play a role by demanding procedures they don’t need.

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As a result, the foundation and the nine medical groups have partnered with Consumer Reports and 11 other consumer organizations to disseminate the list to millions of consumers. They hope to start “a long overdue and important conversation between physicians and patients about what care is really needed,’’ Cassel said.

The groups say the list will help combat defensive medicine, the practice of performing tests and procedures out of fear of malpractice lawsuits if a problem is missed. “A lot of doctors say they order things because they are worried about being sued. We hope this list will back them up,’’ Cassel said, by giving physicians sound evidence for their decisions.

The nine organizations that are part of the “Choosing Wisely’’ campaign - American Academy of Allergy, Asthma & Immunology, American Academy of Family Physicians, American College of Cardiology, American College of Physicians, American College of Radiology, American Gastroenterological Association, American Society of Clinical Oncology, American Society of Nephrology, and American Society of Nuclear Cardiology - each reviewed medical evidence over months and settled on a list of five tests and procedures that are often overused.

The complete list includes additional detail about when a test or treatment may be appropriate based on clinical evidence and guidelines. None of the groups estimated the number of unneeded tests performed or their cost.

The list includes widely used treatments, such as giving antibiotics for colds that last a week or less or ordering brain scans for uncomplicated headaches in generally healthy, low-risk patients.

But the specialty societies also include unnecessary tests and treatments given to sick patients, such as bone scans for early-stage prostate and breast cancer with little chance of spreading.

Dr. Lowell Schnipper, an oncologist at Beth Israel Deaconess Medical Center and chair of a national task force on the cost of cancer care, said that even when professional organizations issue clinical guidelines for oncologists to follow, many don’t adhere to them.

“Cancer is to some extent a special case,’’ he said. “The anxiety of patients is high and doctors want to make sure every single ‘i’ is dotted and to assure the patient that everything possible is being done.’’

It can be even harder for doctors to say no to patients with advanced disease, even if the test or treatment will do them no good, said Dr. Daniel Weiner, a nephrologist at Tufts Medical Center who helped draw up the list of potentially unneeded procedures for the nephrology society.

For example, that group recommends against routine cancer screenings such as mammography, colonoscopy, prostate-specific antigen, and Pap smears for patients on dialysis with limited life expectancy.

“If you’re doing it to prevent something years down the road, you have to take into account what the time horizon is,’’ Weiner said. “These are very very hard conversations.’’

In other cases, such as cardiac stress tests given in a doctor’s office, physicians may have financial incentives for performing the test, the societies’ leaders said. Or, as with routine chest X-rays before surgery, the procedure “has become habit when there is no reason for it,’’ said Dr. Steven Weinberger, chief executive of the American College of Physicians.

About a year and a half ago, Weinberger tore cartilage in his knee and needed surgery. When he scheduled the procedure, the receptionist said he needed a chest X-ray and various other tests even though he is healthy and never smoked or had lung disease.

“If anyone should have been able to say, ‘I don’t need that,’ I should have been. I am embarrassed to say I chickened out. You don’t want to rock the boat. You don’t want to be viewed as an uncooperative patient. This is one reason it’s so important that we get patients involved in this discussion.’’